JP6732833B2 - Vehicle power supply - Google Patents

Description

The present invention relates to a vehicle power supply device mounted on a vehicle.

A vehicle such as an automobile is equipped with a generator such as a motor generator, an alternator or an ISG (Integrated Starter Generator). From the viewpoint of improving the fuel efficiency of the vehicle, the generator is controlled to a regenerative power generation state during deceleration traveling (see Patent Documents 1 and 2). Further, when controlling the generator to the regenerative power generation state, the throttle valve is opened to reduce the pump loss of the engine. As a result, the power generation torque of the generator can be increased while suppressing an increase in vehicle deceleration, and the generated power can be increased to improve the fuel consumption performance of the vehicle.

JP-A-9-284916 JP, 2000-97068, A

However, when the throttle valve is opened during deceleration, that is, when the intake air amount of the engine is increasing and the engine speed decreases and fuel injection is restarted, the engine torque decreases. There is a risk that the output will be large. As described above, opening the throttle valve more than necessary is a factor that causes an excessive increase in engine torque. Therefore, it is required to appropriately control the throttle valve.

An object of the present invention is to properly control the throttle valve.

The vehicle power supply device of the present invention is a vehicle power supply device mounted on a vehicle, and is provided in a generator connected to an engine, a power storage unit connected to the generator, and an intake system of the engine. While controlled on the open side above the reference value during regenerative power generation of the generator, on the closed side below the reference value from the end of regenerative power generation of the generator to the start of fuel injection of the engine A throttle valve, a power generation control unit that regenerates power from the generator during deceleration travel, and a current upper limit value that is an upper limit value of the charging current for the power storage unit based on the temperature of the power storage unit. An opening upper limit setting unit that lowers and sets the opening upper limit value of the throttle valve as the value decreases, and a throttle control unit that controls the throttle valve within the range of the opening upper limit value or less during regenerative power generation of the generator. In the region where the temperature of the power storage unit exceeds a first temperature threshold, the opening upper limit setting unit reduces the current upper limit value as the temperature of the power storage unit increases, while the temperature of the power storage unit In a region where is lower than the second temperature threshold lower than the first temperature threshold, the current upper limit value is lowered as the temperature of the power storage unit is lowered.
The vehicle power supply device of the present invention is a vehicle power supply device mounted on a vehicle, and is provided in a generator connected to an engine, a power storage unit connected to the generator, and an intake system of the engine. While controlled on the open side above the reference value during regenerative power generation of the generator, on the closed side below the reference value from the end of regenerative power generation of the generator to the start of fuel injection of the engine A throttle valve, a power generation control unit that regenerates power from the generator during deceleration travel, an opening upper limit setting unit that sets an opening upper limit value of the throttle valve based on the temperature of the power storage unit, and the power generation. A throttle control unit that controls the throttle valve within a range that is equal to or less than the opening upper limit value during regenerative power generation of the machine, the opening upper limit setting unit having a temperature of the power storage unit exceeding a first temperature threshold value. In the region, the opening upper limit value is decreased as the temperature of the power storage unit rises, while in the region where the temperature of the power storage unit falls below a second temperature threshold value lower than the first temperature threshold value, the temperature of the power storage unit lowers. Along with this, the opening upper limit value is lowered.

According to the present invention, the opening upper limit setting unit that sets the opening upper limit value of the throttle valve based on the temperature of the power storage unit, and the throttle that controls the throttle valve within the range of the opening upper limit value or less during regenerative power generation of the generator And a control unit. Thereby, the throttle valve can be appropriately controlled.

FIG. 1 is a schematic diagram showing a configuration example of a vehicle equipped with a vehicle power supply device that is an embodiment of the present invention. It is the circuit diagram which showed an example of the power supply circuit simply. It is a schematic diagram showing an example of a control system with which a power supply device for vehicles is provided. It is a figure which shows an example of a current supply condition when controlling a starter generator to a combustion power generation state. It is a figure which shows an example of a current supply condition when controlling a starter generator to a power generation halt state. It is a figure which shows an example of a current supply condition when controlling a starter generator to a regenerative power generation state. It is a figure which shows an example of a current supply condition when controlling a starter generator to a power running state. 6 is a timing chart showing an example of operating states of a starter generator, a throttle valve, a lockup clutch, and the like in regenerative power generation control. (A)-(c) is the schematic which shows an example of the operating condition of the power unit in regenerative electric power generation control. It is a diagram which shows an example of the relationship between a battery temperature and a current upper limit. It is a diagram which shows an example of a relationship between an electric current upper limit and an opening upper limit. 5 is a timing chart showing an example of changes in throttle opening and charging current during regenerative power generation. 5 is a timing chart showing an example of changes in throttle opening and charging current during regenerative power generation. (A) is a diagram showing an example of the relationship between the battery temperature and the current upper limit, and (b) is a diagram showing an example of the relationship between the current upper limit and the opening upper limit. (A) is a diagram showing an example of the relationship between the state of charge and the current upper limit value, and (b) is a diagram showing an example of the relationship between the current upper limit value and the opening degree upper limit value. (A) is a diagram showing an example of the relationship between the state of charge and the current upper limit value, and (b) is a diagram showing an example of the relationship between the current upper limit value and the opening degree upper limit value. (A) is a diagram showing an example of the relationship between the battery temperature and the opening degree upper limit value, and (b) is a diagram showing an example of the relationship between the battery temperature and the opening degree upper limit value. (A) is a diagram showing an example of the relationship between the charging state and the opening degree upper limit value, and (b) is a diagram showing an example of the relationship between the charging state and the opening degree upper limit value.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Vehicle configuration]
FIG. 1 is a schematic diagram showing a configuration example of a vehicle 11 in which a vehicle power supply device 10 according to an embodiment of the present invention is mounted. As shown in FIG. 1, a vehicle 11 is equipped with a power unit 13 using an engine 12 as a power source. A starter generator (generator) 16 is connected to a crankshaft 14 of the engine 12 via a belt mechanism 15. A transmission mechanism 18 is connected to the engine 12 via a torque converter 17, and wheels 20 are connected to the transmission mechanism 18 via a differential mechanism 19 or the like. An exhaust manifold 22 that constitutes the exhaust system 21 of the engine 12 is provided with a catalytic converter 23 that purifies exhaust gas.

A lockup clutch 24 is incorporated in the torque converter 17 connected to the crankshaft 14 of the engine 12. By controlling the lockup clutch 24 to be in the engaged state, the engine 12 and the transmission mechanism 18 are connected via the lockup clutch 24. On the other hand, by controlling the lockup clutch 24 to the released state, the engine 12 and the speed change mechanism 18 are connected via the torque converter 17. In order to switch the operating state of the lockup clutch 24, the torque converter 17 is connected to a valve unit 25 including an electromagnetic valve and an oil passage, and the valve unit 25 is connected to a mission controller 26 including a microcomputer. ..

An intake manifold 31 that constitutes an intake system 30 of the engine 12 is provided with a throttle valve 32 that adjusts an intake air amount. The intake air amount of the engine 12 can be increased by opening the throttle valve 32 and expanding the flow passage area. On the other hand, by closing the throttle valve 32 and reducing the flow passage area, the intake air amount of the engine 12 can be reduced. Further, the engine 12 is provided with an injector 33 for injecting fuel into the intake port and the cylinder. By injecting the fuel from the injector 33, the engine 12 is controlled to the fuel injection state, while stopping the fuel injection from the injector 33 controls the engine 12 to the fuel cut state. Further, the engine 12 is provided with an ignition device 34 including an igniter and an ignition coil. By controlling the ignition timing by the ignition device 34, the engine torque, the combustion temperature of the air-fuel mixture, and the like can be controlled. An engine controller 35 including a microcomputer is connected to the throttle valve 32, the injector 33, and the ignition device 34.

The starter generator 16 connected to the engine 12 is a so-called ISG (Integrated Starter Generator) that functions as a generator and an electric motor. The starter generator 16 functions not only as a generator driven by the crankshaft 14, but also as an electric motor that rotates the crankshaft 14. For example, the starter generator 16 functions as an electric motor when the engine 12 is restarted in the idling stop control or when the engine 12 is assist-driven at the time of starting or accelerating. The starter generator 16 has a stator 40 having a stator coil and a rotor 41 having a field coil. Further, the starter generator 16 is provided with an ISG controller 42 including an inverter, a regulator, a microcomputer, etc. for controlling the energization state of the stator coil and the field coil. By controlling the energization state of the field coil and the stator coil by the ISG controller 42, the power generation voltage, power generation torque, power running torque and the like of the starter generator 16 are controlled.

[Power supply circuit]
The power supply circuit 50 provided in the vehicle 11 will be described. FIG. 2 is a circuit diagram briefly showing an example of the power supply circuit 50. As shown in FIG. 2, the power supply circuit 50 includes a lithium ion battery (electric storage body) 51 electrically connected to the starter generator 16 and a lead battery 52 electrically connected to the starter generator 16 in parallel with the lithium ion battery 51. , Are provided. The terminal voltage of the lithium ion battery 51 is designed to be higher than the terminal voltage of the lead battery 52 in order to positively discharge the lithium ion battery 51. Further, in order to positively charge and discharge the lithium ion battery 51, the internal resistance of the lithium ion battery 51 is designed to be smaller than the internal resistance of the lead battery 52.

A positive electrode line 53 is connected to the positive electrode terminal 16a of the starter generator 16, a positive electrode line 54 is connected to the positive electrode terminal 51a of the lithium ion battery 51, and a positive electrode line 55 is connected to the positive electrode terminal 52a of the lead battery 52. These positive electrode lines 53 to 55 are connected to each other via a connection point 56. A negative electrode line 57 is connected to the negative electrode terminal 16b of the starter generator 16, a negative electrode line 58 is connected to the negative electrode terminal 51b of the lithium ion battery 51, and a negative electrode line 59 is connected to the negative electrode terminal 52b of the lead battery 52. It These negative electrode lines 57 to 59 are connected to each other via a reference potential point 60.

The positive electrode line 55 of the lead battery 52 is provided with a switch SW1 that can be switched between an on state and an off state. By controlling the switch SW1 to the off state, the power supply system 61 including the lithium-ion battery 51 and the starter generator 16 and the power supply system 62 including the lead battery 52 and the electric device group 66 described later can be separated from each other. The positive electrode line 54 of the lithium-ion battery 51 is provided with a switch SW2 that can be switched between an on state and an off state. The lithium ion battery 51 can be disconnected from the power supply circuit 50 by controlling the switch SW2 to the off state.

These switches SW1 and SW2 may be switches composed of semiconductor elements such as MOSFETs, or may be switches that mechanically open and close the contacts using electromagnetic force or the like. Further, the ON state of the switches SW1 and SW2 means an energized state or a conductive state which is electrically connected, and the OFF state of the switches SW1 and SW2 means a non-energized state or an electrically disconnected state. It means the state. The switches SW1 and SW2 are also called relays and contactors.

As shown in FIG. 1, the power supply circuit 50 is provided with a battery module 63. The battery module 63 incorporates the lithium ion battery 51 and the switches SW1 and SW2. Further, the battery module 63 is provided with a battery controller 64 including a microcomputer. The battery controller 64 has a function of monitoring the state of charge SOC, charge/discharge current, terminal voltage, cell temperature, internal resistance, etc. of the lithium-ion battery 51, and a function of controlling the switches SW1 and SW2. The state of charge (SOC) is the ratio of the amount of electricity stored to the design capacity of the battery.

As shown in FIG. 1, the positive electrode line 55 of the lead battery 52 is connected to an electric device group 66 including electric devices 65 such as headlights. Further, a fuse 67 that protects the electric device group 66 and the like is provided on the positive electrode line 55 of the lead battery 52. Further, the negative electrode line 59 of the lead battery 52 is provided with a battery sensor 68 that detects a charging/discharging current, a terminal voltage, a charge state, and the like.

[Control system]
FIG. 3 is a schematic diagram showing an example of a control system included in the vehicle power supply device 10. As shown in FIGS. 1 and 3, the vehicle power supply device 10 has a main controller 70 including a microcomputer or the like for controlling the engine 12, the starter generator 16 and the like in cooperation with each other. The main controller 70 includes a fuel control unit 71 that controls the injector 33, an ignition control unit 72 that controls the ignition device 34, a throttle control unit 73 that controls the throttle valve 32, and a power generation control unit 74 that controls the starter generator 16. Also, a lockup control unit 75 for controlling the lockup clutch 24 and the like are provided.

The main controller 70 and the above-mentioned controllers 26, 35, 42, 64 are communicatively connected to each other via an in-vehicle network 77 such as CAN or LIN. The main controller 70 controls the starter generator 16, the lockup clutch 24, the throttle valve 32, the injector 33, the ignition device 34, and the like based on information from various controllers and sensors. The main controller 70 controls the operating state of the starter generator 16 via the ISG controller 42. Further, the main controller 70 controls the operating state of the lockup clutch 24 via the mission controller 26. Further, the main controller 70 controls the operating states of the throttle valve 32, the injector 33 and the ignition device 34 via the engine controller 35.

As shown in FIG. 3, as sensors connected to the main controller 70, an accelerator sensor 80 for detecting an operation amount of an accelerator pedal, a brake sensor 81 for detecting an operation amount of a brake pedal, and an opening degree of a throttle valve 32 are detected. A throttle opening sensor 82, an engine speed sensor 83 that detects the engine speed that is the rotation speed of the engine 12, and a vehicle speed sensor 84 that detects the vehicle speed that is the traveling speed of the vehicle 11. Further, the main controller 70 receives operation information of the injector 33, the ignition device 34, the throttle valve 32, the starter generator 16, the lockup clutch 24, the battery module 63, etc. from each controller.

[Starter generator control]
The power generation control unit 74 of the main controller 70 sets the target power generation voltage of the starter generator 16 based on the state of charge SOC of the lithium ion battery 51. Then, the power generation control unit 74 outputs the target power generation voltage to the ISG controller 42, and the ISG controller 42 controls the power generation voltage of the starter generator 16 in accordance with the target power generation voltage. Control dormancy.

FIG. 4 is a diagram showing an example of the current supply state when the starter generator 16 is controlled to the combustion power generation state. For example, when the state of charge SOC of the lithium-ion battery 51 is below a predetermined lower limit value, the starter generator 16 is driven to generate power by the engine power in order to charge the lithium-ion battery 51 and raise the state of charge SOC. As described above, when the starter generator 16 is controlled to the combustion power generation state, the power generation voltage of the starter generator 16 is raised and the power generation voltage applied to the lithium ion battery 51 is adjusted to be higher than the terminal voltage. As a result, as shown by a black arrow in FIG. 4, a current is supplied from the starter generator 16 to the lithium ion battery 51, the electric device group 66, the lead battery 52, and the like, and the lithium ion battery 51 and the lead battery 52. Is slowly charged.

FIG. 5 is a diagram showing an example of a current supply state when the starter generator 16 is controlled to a power generation stop state. For example, when the state of charge SOC of the lithium-ion battery 51 exceeds a predetermined upper limit value, the lithium-ion battery 51 is positively discharged, so that the drive of the starter generator 16 using engine power is stopped. As described above, when the starter generator 16 is controlled to the power generation stop state, the power generation voltage of the starter generator 16 is lowered, and the power generation voltage applied to the lithium ion battery 51 is adjusted to be lower than the terminal voltage. As a result, as shown by the black arrow in FIG. 5, a current is supplied from the lithium-ion battery 51 to the electric device group 66, so that the power generation drive of the starter generator 16 can be suppressed or stopped, and the engine load can be reduced. Can be reduced.

As described above, the power generation control unit 74 of the main controller 70 controls the starter generator 16 to the combustion power generation state or the power generation stop state based on the state of charge SOC. However, when the vehicle decelerates, a large amount of kinetic energy is collected to reduce fuel consumption. It is necessary to improve performance. Therefore, when the vehicle decelerates, the power generation voltage of the starter generator 16 is greatly increased, and the starter generator 16 is controlled to the regenerative power generation state. As a result, the generated electric power of the starter generator 16, that is, the regenerative electric power can be increased, so that the kinetic energy can be positively converted into the electric energy and recovered, and the energy efficiency of the vehicle 11 can be improved to improve the fuel consumption performance. Can be made.

As described above, whether or not to control the starter generator 16 to the regenerative power generation state is determined based on the operation status of the accelerator pedal and the brake pedal. That is, during deceleration traveling in which the accelerator pedal is released and during deceleration traveling in which the brake pedal is depressed, the engine 12 is in the fuel cut state, so the starter generator 16 is in the regenerative power generation state. To be done. During acceleration running or steady running in which the accelerator pedal is depressed, the engine 12 is controlled to the fuel injection state, so the starter generator 16 is controlled to the combustion power generation state or the power generation halt state.

Here, FIG. 6 is a diagram showing an example of a current supply state when the starter generator 16 is controlled in the regenerative power generation state. When the starter generator 16 is controlled in the regenerative power generation state, the power generation voltage of the starter generator 16 is raised more than in the combustion power generation state described above, and the power generation voltage applied to the lithium ion battery 51 is raised more than the terminal voltage. As a result, a large current is supplied from the starter generator 16 to the lithium ion battery 51 and the lead battery 52 as indicated by the black arrow in FIG. 6, so that the lithium ion battery 51 and the lead battery 52 are rapidly discharged. Be charged. Further, since the internal resistance of the lithium ion battery 51 is smaller than the internal resistance of the lead battery 52, most of the generated current is supplied to the lithium ion battery 51.

As shown in FIGS. 4 to 6, when the starter generator 16 is controlled to the combustion power generation state, the regenerative power generation state, and the power generation halt state, the switches SW1 and SW2 are held in the ON state. That is, in the vehicle power supply device 10, the charge/discharge of the lithium ion battery 51 can be controlled only by controlling the generated voltage of the starter generator 16 without performing the switching control of the switches SW1 and SW2. As a result, charging/discharging of the lithium ion battery 51 can be easily controlled, and the durability of the switches SW1 and SW2 can be improved.

Further, FIG. 7 is a diagram showing an example of the current supply state when the starter generator 16 is controlled to the power running state. As shown in FIG. 7, when the starter generator 16 is controlled to the power running state, the switch SW1 is switched from the on state to the off state. That is, the switch SW1 is switched from the ON state to the OFF state when the engine 12 is started and rotated by the starter generator 16 or when the engine 12 is assist-driven by the starter generator 16. As a result, the power supply systems 61 and 62 are separated from each other, so that even when a large current is supplied from the lithium-ion battery 51 to the starter generator 16, a momentary voltage drop to the electric device group 66 and the like is prevented. The electric device group 66 and the like can be normally operated.

[Regenerative power generation control]
An example of the regenerative power generation control executed by the vehicle power supply device 10 will be described. FIG. 8 is a timing chart showing an example of operating states of the starter generator 16, the throttle valve 32, the lockup clutch 24, and the like in the regenerative power generation control. The traveling situation shown in FIG. 8 is a coast traveling situation in which the depression of the accelerator pedal and the brake pedal is released. 9A to 9C are schematic diagrams showing an example of the operating state of the power unit 13 in the regenerative power generation control. 9(a) shows the situation at time t1 shown in FIG. 8, FIG. 9(b) shows the situation at time t2 shown in FIG. 8, and FIG. 9(c) shows the situation in FIG. The situation at the indicated time t3 is shown.

The “LU clutch” shown in FIG. 8 is the lockup clutch 24, the “ISG” is the starter generator 16, and the “Th” is the opening of the throttle valve 32 (hereinafter referred to as the throttle opening). , “Pi” is the intake pipe pressure in the intake manifold 31. “Ne” shown in FIGS. 8 and 9 is the engine speed that is the rotation speed of the input side (engine side) of the lockup clutch 24, and “Nt” is the output side (wheel side) of the lockup clutch 24. It is the turbine speed that is the rotation speed. Further, in this specification, the opening side of the throttle valve 32 means the side where the throttle opening exceeds a predetermined reference value X1, and the closing side of the throttle valve 32 means the throttle opening is the reference value X1. It means the side below.

(Time t1)
As shown at time t1 in FIG. 8, during coasting in which the accelerator pedal is released, the engine 12 is controlled to the fuel cut state (reference numeral a1) and the starter generator 16 is controlled to the regenerative power generation state (reference numeral b1). ), the lockup clutch 24 is controlled to the engaged state (reference numeral c1). That is, as shown in FIG. 9A, the lockup clutch 24 is engaged during coasting, so that the rotational force can be efficiently transmitted from the wheel 20 to the starter generator 16 as indicated by an arrow α1. it can. As a result, the regenerative torque of the starter generator 16, that is, the power generation torque of the starter generator 16 can be increased, and the power generated during coasting can be increased.

Further, as shown at time t1 in FIG. 8, the throttle valve 32 is controlled to the open side during coast running in which regenerative power generation is performed (reference numeral d1). In this way, by controlling the throttle valve 32 to the open side, the intake air amount of the engine 12 can be increased and the pump loss of the engine 12 can be increased as shown by the outlined arrow in FIG. Can be reduced. As a result, engine braking during deceleration of the vehicle can be reduced, so that the generated torque can be increased without excessively increasing the vehicle deceleration, and the generated power can be increased to recover a large amount of kinetic energy. When controlling the throttle valve 32 on the open side, the throttle opening is adjusted so that the negative pressure of a vacuum booster (not shown) or the like does not become insufficient.

(Time t2)
As shown at time t2 in FIG. 8, when the lockup clutch 24 is switched from the engaged state to the released state (reference numeral c2), the throttle valve 32 is controlled from the open side toward the close side (reference numeral d2). Further, as shown at time t2, when the lockup clutch 24 is switched from the engaged state to the released state (reference numeral c2), the starter generator 16 is controlled from the regenerative power generation state to the power running state (reference numeral b2). Then, when the starter generator 16 is controlled to the power running state for a predetermined time, the starter generator 16 is switched from the power running state to the power generation halt state (reference numeral b3). The conditions for releasing the lockup clutch 24 during deceleration include that the vehicle speed is below a predetermined value, the vehicle deceleration is above a predetermined value, and the engine speed is below a predetermined value. The conditions are not limited to.

As described above, when the lockup clutch 24 is released during deceleration traveling, the throttle valve 32 is controlled to the closing side (reference numeral d2). As a result, as will be described later, the intake pipe pressure Pi in the intake manifold 31 can be decreased (reference numeral e1) and the intake air amount of the engine 12 can be decreased in preparation for restarting fuel injection. Further, as described above, when the lockup clutch 24 is released during deceleration traveling, the starter generator 16 is controlled to the power running state (reference numeral b2). As described above, by making the starter generator 16 power-run, the motor torque is transmitted from the starter generator 16 to the engine 12 as indicated by an arrow α2 in FIG. 9B, and as shown by a symbol f1 in FIG. The engine speed Ne can be gradually reduced. As a result, as will be described later, it is possible to secure a time until the fuel injection is restarted, and it is possible to sufficiently reduce the intake air amount of the engine 12.

(Time t3)
As shown at time t3 in FIG. 8, when the engine speed Ne reaches a predetermined lower limit value X2 (reference numeral f2), fuel injection to the engine 12 is restarted (reference numeral a2) from the viewpoint of preventing engine stall. That is, when the engine speed Ne decreases and reaches the lower limit value X2, the engine 12 is switched from the fuel cut state to the fuel injection state. As described above, when fuel injection to the engine 12 is restarted, engine torque is output in a direction of accelerating the vehicle 11, so that the vehicle deceleration is greatly reduced during deceleration, which may give an occupant an uncomfortable feeling. There is.

However, as described above, the vehicle power supply device 10 controls the throttle valve 32 to the closing side when the lockup clutch 24 is released (reference numeral d2). As a result, the intake air amount of the engine 12 can be reduced, so that the engine torque output when the fuel injection is restarted can be suppressed. Further, when the lockup clutch 24 is released, the vehicle power supply device 10 controls the starter generator 16 in the power running state (reference numeral b2). As a result, the engine speed Ne can be gently reduced (reference numeral f1), so that it is possible to secure a time period until the engine speed Ne reaches the lower limit value X2 and fuel injection is restarted. As a result, the amount of intake air of the engine 12 can be sufficiently reduced, and the engine torque output when fuel injection is restarted can be suppressed.

Further, the vehicle power supply device 10 executes the ignition retard control for delaying the ignition timing of the engine 12 when the fuel injection of the engine 12 is restarted, as indicated by reference sign g1. As a result, the engine torque can be further suppressed, so that fuel injection can be restarted without giving an occupant an uncomfortable feeling. In the ignition retard control, the retard amount of the ignition timing is set larger as the intake air amount is larger, and the retard amount of the ignition timing is set smaller as the intake air amount is smaller. It is needless to say that the ignition retard control may be stopped when the intake air amount is small and the engine torque is sufficiently suppressed.

[Throttle valve opening upper limit value]
As described above, the throttle valve 32 is controlled to the open side during regenerative power generation in order to increase the regenerative power generation amount of the starter generator 16. However, controlling the throttle valve 32 to the open side increases the intake air amount. This is a factor, and is a factor that increases the engine torque when the fuel injection is restarted. Therefore, as shown in FIG. 3, the main controller 70 is provided with an opening upper limit setting unit 76 that sets the opening upper limit value Thmax of the throttle valve 32 so as not to excessively increase the intake air amount during regenerative power generation. Has been.

As will be described later, the opening degree upper limit setting unit 76 of the main controller 70 sets the opening degree upper limit value Thmax of the throttle valve 32 based on the state of the lithium ion battery 51. Then, the throttle control unit of the main controller 70 controls the throttle valve 32 within the range of the opening degree upper limit value Thmax or less during the regenerative power generation of the starter generator 16. That is, during regenerative power generation of the starter generator 16, the throttle valve 32 is controlled on the open side as described above, but when the opening upper limit value Thmax is set small, the throttle valve 32 is controlled on the closed side. It will be.

Hereinafter, an example of a procedure for setting the opening upper limit value Thmax will be described. FIG. 10 is a diagram showing an example of the relationship between battery temperature TB and current upper limit value imax. FIG. 11 is a diagram showing an example of the relationship between the current upper limit value imax and the opening degree upper limit value Thmax.

The opening upper limit setting unit 76 of the main controller 70 sets the current upper limit value imax of the lithium ion battery 51 based on the temperature of the lithium ion battery 51 (hereinafter, referred to as battery temperature TB). The current upper limit value imax is the upper limit value of the charging current allowed for the lithium ion battery 51. As shown in FIG. 10, in the high temperature region in which the battery temperature TB exceeds the first temperature threshold value TH, the current upper limit value imax decreases as the battery temperature TB increases. In this way, when the battery temperature TB changes in the high temperature region, the battery temperature TB is lowered to protect the lithium ion battery 51. Therefore, the charging current of the lithium ion battery 51 is suppressed by lowering the current upper limit value imax. To be done.

Further, as shown in FIG. 10, in the low temperature region in which the battery temperature TB is lower than the second temperature threshold TL lower than the first temperature threshold TH, the current upper limit value imax is lowered as the battery temperature TB is lowered. As described above, when the battery temperature TB changes in the low temperature region, it is difficult to charge the lithium ion battery 51 because the internal resistance of the lithium ion battery 51 increases. Therefore, when the battery temperature TB changes in the low temperature range, the charging current of the lithium ion battery 51 is suppressed by lowering the current upper limit value imax.

When battery temperature TB falls within the range of temperature thresholds TL to TH, current value ia at which the charging current does not reach is set as current upper limit value imax. That is, when battery temperature TB falls within the range of temperature thresholds TL to TH, current upper limit value imax is set to be significantly high so that the charging current of lithium ion battery 51 is not limited.

Next, the opening upper limit setting unit 76 of the main controller 70 sets the opening upper limit value Thmax of the throttle valve 32 based on the current upper limit value imax of the lithium ion battery 51. The opening degree upper limit value Thmax is an upper limit value of the throttle opening degree Th that is allowed during regenerative power generation of the starter generator 16. As shown in FIG. 11, as the current upper limit value imax of the lithium-ion battery 51 decreases, the opening degree upper limit value Thmax of the throttle valve 32 decreases. As described above, by setting the opening upper limit value Thmax based on the current upper limit value imax, the throttle valve 32 can be appropriately controlled according to the regenerative power generation state.

That is, the situation in which the current upper limit value imax of the lithium ion battery 51 is lowered is a situation in which the power generation current of the starter generator 16 is limited, and the power generation torque of the starter generator 16 is limited. That is, the vehicle deceleration is not excessively increased by the power generation torque during the regenerative power generation, and the throttle opening Th is allowed to decrease. As described above, in a situation where the throttle opening Th is allowed to decrease, that is, the current upper limit value imax decreases, the opening upper limit value Thmax is lowered, so the throttle valve 32 is closed to reduce the intake air amount. Therefore, the engine torque at the time of restarting fuel injection can be suppressed.

In this way, by setting the opening degree upper limit value Thmax of the throttle valve 32 based on the battery temperature TB indicating the state of the lithium ion battery 51, the throttle valve 32 can be appropriately controlled during regenerative power generation.

[Lithium-ion battery high temperature range]
Next, the transition of the throttle opening Th in the high temperature region of the lithium ion battery 51 will be described with reference to a timing chart. FIG. 12 is a timing chart showing an example of changes in the throttle opening Th and the charging current ic during regenerative power generation. FIG. 12 shows a situation in which the battery temperature TB exceeds the first temperature threshold value TH. Further, FIG. 12 shows a situation in which the acceleration traveling and the deceleration traveling are repeated, that is, a situation in which regenerative power generation of the starter generator 16 is repeated. It should be noted that FIG. 12 shows the throttle opening Th only during deceleration traveling, and does not show the throttle opening Th during acceleration traveling or steady traveling.

As indicated by the symbol α in FIG. 12, during deceleration traveling, the starter generator 16 is controlled to the regenerative power generation state, and the charging current ic is supplied to the lithium ion battery 51 (reference symbol a1). Further, during deceleration, the engine brake is reduced to increase the power generation torque, so that the throttle valve 32 is opened and the throttle opening Th is expanded (reference numeral b1). After that, charging and discharging of the lithium-ion battery 51 are repeated, and when the battery temperature TB rises and reaches the first temperature threshold value TH (reference numeral c1), reduction of the current upper limit value imax is started based on the battery temperature TB (reference numeral d1). ), reduction of the opening upper limit value Thmax is started based on the current upper limit value imax (reference numeral e1).

Thereafter, when the current upper limit value imax decreases as the battery temperature TB increases, the charging current ic is limited by the current upper limit value imax (reference numeral a2). When the opening upper limit value Thmax decreases as the current upper limit value imax decreases, the throttle opening Th is limited by the opening upper limit value Thmax (reference numeral b2). As described above, the situation where the battery temperature TB rises and the charging current ic is limited is a situation in which the throttle opening Th is allowed to decrease due to the decrease in the power generation torque. Therefore, the throttle opening Th is limited by the opening upper limit value Thmax to reduce the intake air amount and suppress the engine torque when the fuel injection is restarted.

[Lithium-ion battery low temperature range]
Next, transition of the throttle opening Th in the low temperature region of the lithium ion battery 51 will be described with reference to a timing chart. FIG. 13 is a timing chart showing an example of changes in throttle opening Th and charging current ic during regenerative power generation. FIG. 13 shows a situation in which the battery temperature TB falls below the second temperature threshold value TL. Further, FIG. 13 shows a situation in which acceleration traveling and deceleration traveling are repeated, that is, a situation in which regenerative power generation of the starter generator 16 is repeated. It should be noted that FIG. 13 shows the throttle opening Th only during deceleration traveling, and does not show the throttle opening Th during acceleration traveling or steady traveling.

As shown in FIG. 13, immediately after the start of running in the low temperature environment, the battery temperature TB is in a state of being below the second temperature threshold value TL (reference numeral c1). In this case, the current upper limit value imax is reduced based on the battery temperature TB (reference numeral d1), and the opening degree upper limit value Thmax is reduced based on the current upper limit value imax (reference numeral e1). Under this circumstance, as indicated by the symbol α, when regenerative power generation is performed along with deceleration traveling, the charging current ic is limited by the current upper limit value imax (reference symbol a1), and the throttle opening by the opening upper limit value Thmax. The opening Th is limited (reference numeral b1). As described above, the situation in which the battery temperature TB decreases and the charging current ic is limited is a situation in which the throttle opening Th is allowed to decrease due to the decrease in the power generation torque. Therefore, the throttle opening Th is limited by the opening upper limit value Thmax to reduce the intake air amount and suppress the engine torque when the fuel injection is restarted.

After that, charging and discharging of the lithium ion battery 51 are repeated, and when the battery temperature TB rises and reaches the second temperature threshold value TL (reference numeral c2), the limitation of the charging current ic by the current upper limit value imax is released (reference numeral d2). The restriction of the throttle opening Th by the opening upper limit value Thmax is released (reference numeral e2). Under this situation, when regenerative power generation is performed along with deceleration traveling, charging current ic is supplied to lithium-ion battery 51 without being limited by current upper limit value imax (reference numeral a2). Further, when the regenerative power generation control is executed along with the deceleration traveling, the engine brake is lowered to increase the power generation torque, so that the throttle opening Th is expanded without being limited by the opening upper limit value Thmax (reference numeral b2). ).

[Other methods for setting the upper limit of opening]
In the example shown in FIG. 10, in the region where the battery temperature TB exceeds the first temperature threshold value TH, the current upper limit value imax is continuously decreased as the battery temperature TB increases, but the present invention is not limited to this. Further, in the example shown in FIG. 10, in the region where the battery temperature TB is lower than the second temperature threshold TL, the current upper limit value imax is continuously decreased as the battery temperature TB decreases, but the present invention is not limited to this. .. Further, in the example shown in FIG. 11, the opening upper limit value Thmax is continuously decreased as the current upper limit value imax decreases, but the present invention is not limited to this. Here, FIG. 14A is a diagram showing an example of the relationship between the battery temperature TB and the current upper limit value imax, and FIG. 14B is an example of the relationship between the current upper limit value imax and the opening upper limit value Thmax. FIG.

As shown in FIG. 14A, in the region where the battery temperature TB exceeds the first temperature threshold value TH, the current upper limit value imax may be set in a stepwise manner as the battery temperature TB increases. Further, as shown in FIG. 14A, in the region where the battery temperature TB is lower than the second temperature threshold value TL, the current upper limit value imax may be set in a stepwise manner as the battery temperature TB decreases. Further, as shown in FIG. 14B, the opening upper limit value Thmax may be set stepwise as the current upper limit value imax decreases. Even if the opening upper limit value Thmax is set based on the battery temperature TB using the diagrams shown in FIGS. 14A and 14B, the throttle valve 32 can be appropriately controlled.

[Other Embodiment 1]
In the above description, the opening upper limit value Thmax of the throttle valve 32 is set based on the battery temperature TB indicating the state of the lithium ion battery 51, but the present invention is not limited to this. For example, the opening degree upper limit value Thmax of the throttle valve 32 may be set based on the state of charge SOC indicating the state of the lithium ion battery 51. Here, FIG. 15A is a diagram showing an example of the relationship between the state of charge SOC and the current upper limit value imax, and FIG. 15B is an example of the relationship between the current upper limit value imax and the opening degree upper limit value Thmax. FIG. 16(a) is a diagram showing an example of the relationship between the state of charge SOC and the current upper limit value imax, and FIG. 16(b) is an example of the relationship between the current upper limit value imax and the opening degree upper limit value Thmax. It is a diagram showing.

The opening upper limit setting unit 76 of the main controller 70 sets the current upper limit value imax of the lithium ion battery 51 based on the state of charge SOC of the lithium ion battery 51. The current upper limit value imax is the upper limit value of the charging current allowed for the lithium ion battery 51. As shown in FIG. 15A or FIG. 16A, as the state of charge SOC of the lithium ion battery 51 increases, the current upper limit value imax of the lithium ion battery 51 decreases. As described above, when the state of charge SOC of the lithium ion battery 51 rises, that is, when the lithium ion battery 51 approaches the full charge state, charging is difficult because the internal resistance of the lithium ion battery 51 rises. Therefore, when the state of charge SOC rises, the charging current of the lithium ion battery 51 is suppressed by lowering the current upper limit value imax.

Next, the opening upper limit setting unit 76 of the main controller 70 sets the opening upper limit value Thmax of the throttle valve 32 based on the current upper limit value imax of the lithium ion battery 51. The opening degree upper limit value Thmax is an upper limit value of the throttle opening degree Th that is allowed during regenerative power generation of the starter generator 16. As shown in FIG. 15B or FIG. 16B, as the current upper limit value imax of the lithium ion battery 51 decreases, the opening degree upper limit value Thmax of the throttle valve 32 decreases.

That is, the situation in which the current upper limit value imax of the lithium ion battery 51 is lowered is a situation in which the power generation current of the starter generator 16 is limited, and the power generation torque of the starter generator 16 is limited. That is, the vehicle deceleration is not excessively increased by the power generation torque during the regenerative power generation, and the throttle opening Th is allowed to decrease. As described above, in a situation where the throttle opening Th is allowed to decrease, that is, the current upper limit value imax decreases, the opening upper limit value Thmax is lowered, so the throttle valve 32 is closed to reduce the intake air amount. Therefore, the engine torque at the time of restarting fuel injection can be suppressed.

As described above, even when the opening upper limit value Thmax of the throttle valve 32 is set based on the state of charge SOC indicating the state of the lithium-ion battery 51, the throttle valve 32 can be appropriately controlled during regenerative power generation. It is possible.

[Other Embodiment 2]
In the example shown in FIGS. 10 and 11, the current upper limit value imax is set based on the battery temperature TB and the opening upper limit value Thmax is set based on the current upper limit value imax, but the present invention is not limited to this. Absent. That is, in the example shown in FIGS. 10 and 11, the opening upper limit value Thmax is indirectly set from the battery temperature TB, but the invention is not limited to this, and the opening upper limit value Thmax may be directly set from the battery temperature TB. The value Thmax may be set. Here, FIG. 17A is a diagram showing an example of the relationship between the battery temperature TB and the opening degree upper limit value Thmax, and FIG. 17B is an example of the relationship between the battery temperature TB and the opening degree upper limit value Thmax. FIG.

The opening upper limit setting unit 76 of the main controller 70 sets the opening upper limit value Thmax of the throttle valve 32 based on the battery temperature TB of the lithium ion battery 51. The opening degree upper limit value Thmax is an upper limit value of the throttle opening degree Th that is allowed during regenerative power generation of the starter generator 16. As shown in FIG. 17A or FIG. 17B, in the region where the battery temperature TB exceeds the first temperature threshold value TH, the opening degree upper limit value Thmax is reduced as the battery temperature TB increases. In the region where the battery temperature TB falls below the second temperature threshold TL which is lower than the first temperature threshold TH, the opening degree upper limit value Thmax is lowered as the battery temperature TB falls.

That is, in the region where the battery temperature TB exceeds the first temperature threshold value TH, the battery temperature TB is lowered to protect the lithium ion battery 51, and thus the charging current of the lithium ion battery 51 is suppressed. Further, in a region where the battery temperature TB is lower than the second temperature threshold value TL which is lower than the first temperature threshold value TH, the internal resistance of the lithium ion battery 51 increases, so that the charging current of the lithium ion battery 51 is suppressed. In this way, in the high temperature region and the low temperature region of the lithium ion battery 51, that is, in the region where the charging current is suppressed, the opening degree upper limit value Thmax of the throttle valve 32 is lowered.

The situation where the charging current of the lithium-ion battery 51 is suppressed in the high temperature region and the low temperature region is a situation in which the power generation current of the starter generator 16 is limited, and a situation in which the power generation torque of the starter generator 16 is limited. That is, the vehicle deceleration is not excessively increased by the power generation torque during the regenerative power generation, and the throttle opening Th is allowed to decrease. As described above, in a situation in which the decrease of the throttle opening Th is allowed, that is, in the high temperature region and the low temperature region of the lithium ion battery 51, the opening upper limit value Thmax is lowered, so the throttle valve 32 is closed and the intake air amount is increased. Can be reduced, and the engine torque at the time of restarting fuel injection can be suppressed.

As described above, even when the opening upper limit value Thmax is set directly from the battery temperature TB by using the diagram shown in FIG. 17A or 17B, FIG. Similar to the example shown in FIG. 14, in the high temperature region and the low temperature region of the lithium-ion battery 51, the throttle valve 32 can be closed during regenerative power generation to reduce the intake air amount, and the engine torque at the time of restarting fuel injection is suppressed. be able to. That is, it is possible to appropriately control the throttle valve 32 during regenerative power generation of the starter generator 16.

[Other Embodiment 3]
In the example shown in FIGS. 15 and 16, the current upper limit value imax is set based on the state of charge SOC, and the opening upper limit value Thmax is set based on the current upper limit value imax, but the present invention is not limited to this. Absent. That is, in the examples shown in FIGS. 15 and 16, the opening degree upper limit value Thmax is indirectly set from the state of charge SOC, but the invention is not limited to this, and the opening degree upper limit value Thmax is directly set from the state of charge SOC. The value Thmax may be set. Here, FIG. 18A is a diagram showing an example of the relationship between the state of charge SOC and the opening degree upper limit value Thmax, and FIG. 18B is an example of the relationship between the state of charge SOC and the opening degree upper limit value Thmax. FIG.

The opening upper limit setting unit 76 of the main controller 70 sets the opening upper limit value Thmax of the throttle valve 32 based on the state of charge SOC of the lithium-ion battery 51. The opening degree upper limit value Thmax is an upper limit value of the throttle opening degree Th that is allowed during regenerative power generation of the starter generator 16. As shown in FIG. 18A or FIG. 18B, as the state of charge SOC of the lithium-ion battery 51 increases, the opening degree upper limit value Thmax of the throttle valve 32 decreases.

That is, when the state of charge SOC of the lithium-ion battery 51 rises, that is, when the lithium-ion battery 51 approaches the full-charge state, the internal resistance of the lithium-ion battery 51 rises, making it difficult to charge the lithium-ion battery 51. The charging current of 51 is suppressed. In this way, in a state where the state of charge SOC of the lithium ion battery 51 is high, that is, a state where the charging current is suppressed, the opening degree upper limit value Thmax of the throttle valve 32 is lowered.

The situation where the charging current is suppressed by the high state of charge SOC of the lithium-ion battery 51 is a situation where the power generation current of the starter generator 16 is limited, and the situation where the power generation torque of the starter generator 16 is limited. That is, the vehicle deceleration is not excessively increased by the power generation torque during the regenerative power generation, and the throttle opening Th is allowed to decrease. As described above, in a situation in which the decrease in the throttle opening Th is allowed, that is, in a situation in which the state of charge SOC of the lithium-ion battery 51 is high, the opening upper limit value Thmax is lowered, so that the throttle valve 32 is closed to close the intake air. The amount can be reduced, and the engine torque at the time of restarting fuel injection can be suppressed.

Thus, even when the opening upper limit value Thmax is set directly from the state of charge SOC using the diagram shown in FIG. 18A or FIG. 18B, FIG. 15 and FIG. Similar to the example shown in FIG. 16, when the state of charge SOC of the lithium ion battery 51 is high, the throttle valve 32 can be closed during regenerative power generation to reduce the intake air amount, and the engine torque at the time of restarting fuel injection can be reduced. Can be suppressed. That is, it is possible to appropriately control the throttle valve 32 during regenerative power generation of the starter generator 16.

It is needless to say that the present invention is not limited to the above-mentioned embodiment and can be variously modified without departing from the gist thereof. In the above description, the starter generator 16 that also functions as an electric motor is provided as the generator connected to the engine 12, but the present invention is not limited to this. For example, an alternator that does not function as an electric motor may be adopted as a generator connected to the engine 12. Further, in the above description, the main controller 70 is provided with the throttle control unit 73, the power generation control unit 74, and the opening degree upper limit setting unit 76, but the present invention is not limited to this. The throttle controller 73, the power generation controller 74, or the opening upper limit setting unit 76 may be provided in another controller.

In the above description, the current upper limit value imax is set based on the battery temperature TB and the state of charge SOC. The current upper limit value imax is the upper limit value of the charging current allowed for the lithium ion battery 51, but the current upper limit value imax is not limited to this, and the current upper limit value imax is the generated current output from the starter generator 16. It may be an upper limit value. As described above, during regenerative power generation of the starter generator 16, most of the generated current of the starter generator 16 is supplied to the lithium ion battery 51. That is, during regenerative power generation of the starter generator 16, the upper limit value of the charging current charged in the lithium ion battery 51 and the upper limit value of the generated current output from the starter generator 16 are the upper limit values that are interlocked with each other. Therefore, the upper limit value of the generated current output from the starter generator 16 may be set based on the battery temperature TB and the state of charge SOC, and the opening upper limit value Thmax may be set based on the upper limit value of the generated current. ..

In the above description, coast traveling, which is coasting, is illustrated as the deceleration traveling of the vehicle 11, but the invention is not limited to this. For example, the starter generator 16 may regenerate electric power during decelerating traveling in which the vehicle decelerates while depressing the brake pedal. Further, the opening side of the throttle valve 32 may be a side where the throttle opening exceeds the reference value X1. That is, the opening side of the throttle valve 32 may be in a fully open state or an opening other than fully open. Further, the closed side of the throttle valve 32 may be the side where the throttle opening is below the reference value X1. That is, the closed side of the throttle valve 32 may be in a fully closed state or an opening other than a fully closed state.

In the above description, the ignition retard control of the engine 12 is executed when the fuel injection of the engine 12 is restarted, but the invention is not limited to this. If the engine torque is sufficiently suppressed by the appropriate control of the throttle valve 32 during regenerative power generation, the fuel injection may be restarted without executing the ignition retard control. As described above, by avoiding the ignition retard control, it is possible to reduce the temperature of the exhaust gas and protect the catalytic converter 23.

In the example shown in FIG. 8, the starter generator 16 is controlled to be in the power running state for a predetermined time, but the invention is not limited to this. For example, the starter generator 16 may be controlled in the power running state until the intake pipe pressure Pi reaches a predetermined target value. Further, when the state of charge SOC of the lithium-ion battery 51 is low, the power running control of the starter generator 16 may be stopped. Further, in the example shown in FIG. 8, the starter generator 16 is switched from the power running state to the power generation halt state, but the invention is not limited to this. For example, when the state of charge SOC of the lithium-ion battery 51 is low, the starter generator 16 may be switched from the power running state to the combustion power generation state.

Although two power storage units are connected to the starter generator 16 in the above description, the number of power storage units is not limited to this, and one power storage unit may be connected to the starter generator 16. Further, although the lithium ion battery 51 and the lead battery 52 are adopted in the above description, the invention is not limited to this, and other types of batteries and capacitors may be adopted. Further, in the example shown in FIGS. 1 and 2, the switch SW2 is provided in the positive electrode line 54 of the lithium ion battery 51, but the present invention is not limited to this. For example, the switch SW2 may be provided on the negative electrode line 58 of the lithium-ion battery 51, as shown by the one-dot chain line in FIG.

10 Vehicle Power Supply Device 11 Vehicle 12 Engine 16 Starter Generator (Generator)
30 Intake system 32 Throttle valve 51 Lithium-ion battery (electric storage)
73 Throttle control unit 74 Power generation control unit 76 Opening angle upper limit setting unit TB Battery temperature (temperature of lithium ion battery)
TH first temperature threshold value TL second temperature threshold value imax current upper limit value Thmax opening upper limit value SOC charge state

Claims (2)

A vehicle power supply device mounted on a vehicle, comprising:
A generator connected to the engine,
A power storage unit connected to the generator,
It is provided in the intake system of the engine and is controlled on the opening side that exceeds a reference value during regenerative power generation of the generator, while the regenerative power generation of the generator is completed until fuel injection of the engine is started. A throttle valve controlled on the closing side below the reference value ,
A power generation control unit for regeneratively generating the generator during deceleration travel,
An opening upper limit setting that sets a current upper limit value that is an upper limit value of the charging current for the power storage unit based on the temperature of the power storage unit, and lowers and sets the opening upper limit value of the throttle valve as the current upper limit value decreases. Department,
At the time of regenerative power generation of the generator, a throttle control unit that controls the throttle valve in the range of the opening upper limit value or less,
Have
The opening upper limit setting unit,
In the region where the temperature of the power storage unit exceeds the first temperature threshold value, the current upper limit value is decreased as the temperature of the power storage unit increases,
In a region where the temperature of the power storage unit is below a second temperature threshold value that is lower than the first temperature threshold value, the current upper limit value is lowered as the temperature of the power storage unit decreases.
Vehicle power supply. A vehicle power supply device mounted on a vehicle, comprising:
A generator connected to the engine,
A power storage unit connected to the generator,
It is provided in the intake system of the engine and is controlled on the opening side that exceeds a reference value during regenerative power generation of the generator, while the regenerative power generation of the generator is completed until fuel injection of the engine is started. A throttle valve controlled on the closing side below the reference value ,
A power generation control unit for regeneratively generating the generator during deceleration travel,
An opening degree upper limit setting unit that sets an opening degree upper limit value of the throttle valve based on the temperature of the power storage unit;
At the time of regenerative power generation of the generator, a throttle control unit that controls the throttle valve in a range of the opening upper limit value or less,
Have
The opening upper limit setting unit,
In a region where the temperature of the power storage unit exceeds a first temperature threshold value, the opening upper limit value is decreased as the temperature of the power storage unit increases,
In a region where the temperature of the power storage unit is lower than a second temperature threshold value that is lower than the first temperature threshold value, the opening degree upper limit value is decreased as the temperature of the power storage unit decreases.
Vehicle power supply.

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